1. Field of the Invention
The present embodiments relate to a method of manufacturing a flexible display apparatus, and more particularly, to a flexible display apparatus including a display unit which is easily encapsulated including a thin film transistor.
2. Description of the Related Art
Liquid crystal display devices and organic light emitting display devices which include thin film transistors (TFTs) are widely used in digital cameras, video cameras, or mobile devices such as portable personal digital assistants (PDAs) and cellular phones.
Such a display device used in mobile devices is required to be thin, light and break-resistant. A thin glass substrate may be used to prepare a thin and light display device. In addition, a display device may be prepared using a conventional glass substrate, and then the glass substrate may be thinned by a mechanical or chemical method. However, these processes are complicated and difficult to be practically used.
Thus, there is a need for a flexible display device that may be applied to a curved surface so that the mobile devices may have high portability and various shapes. However, conventional glass substrates are not flexible to accomplish this.
Thus, attempts have been made to form a low-temperature polycrystalline silicon thin-film transistor (Poly-Si TFT) on a plastic substrate. A plastic substrate having a thickness of about 0.2 mm does not easily break, and has lower specific gravity than a glass substrate. Thus, the weight of the plastic substrate may be ⅕ or less of that of the glass substrate and the plastic substrate may be applied to a curved surface.
However, when a thin plastic substrate is used, the weight of a thin-film transistor and a display device, which are formed on the thin plastic substrate, may not be supported by the thin plastic substrate while the thin-film transistor and the display device are sequentially formed on the thin plastic substrate. Thus, the process may not be controlled.
In addition, the upper portion of such a flexible display device needs to be encapsulated in order to protect the flexible display device from oxygen, moisture, etc. However, since encapsulation is usually performed on the display device as a final process for preparing the display device, the temperature used in the process is required not to be greater than 80° C. in order to prevent deterioration of the display device. Also, deterioration of the display device due to plasma during the deposition of inorganic layers needs to be prevented. The present embodiments overcome the above problems as well as provide additional advantages.